private async void Start()
{
startButton.Enabled = false;
status = FindViewById <TextView>(Resource.Id.output);
var devicePicker = FindViewById <Spinner>(Resource.Id.device_picker);
var id = devicePicker.SelectedItem.ToString();
var btAddress = devices[id];
if (btAddress == null)
{
if (ContextCompat.CheckSelfPermission(this, Manifest.Permission.AccessFineLocation) != Permission.Granted)
{
ActivityCompat.RequestPermissions(this, new[] { Manifest.Permission.AccessFineLocation }, 1000);
return;
}
if (launched)
{
return;
}
launched = true;
listener = new NmeaParser.SystemNmeaDevice(ApplicationContext);
}
else //Bluetooth
{
try
{
status.Text = "Opening bluetooth...";
var adapter = Android.Bluetooth.BluetoothAdapter.DefaultAdapter;
var bt = Android.Bluetooth.BluetoothAdapter.DefaultAdapter.GetRemoteDevice(btAddress);
Java.Util.UUID SERIAL_UUID = Java.Util.UUID.FromString("00001101-0000-1000-8000-00805F9B34FB"); //UUID for Serial Device Service
socket = bt.CreateRfcommSocketToServiceRecord(SERIAL_UUID);
try
{
await socket.ConnectAsync();
}
catch (Java.IO.IOException)
{
// This sometimes fails. Use fallback approach to open socket
// Based on https://stackoverflow.com/a/41627149
socket.Dispose();
var m = bt.Class.GetMethod("createRfcommSocket", new Java.Lang.Class[] { Java.Lang.Integer.Type });
socket = m.Invoke(bt, new Java.Lang.Object[] { 1 }) as Android.Bluetooth.BluetoothSocket;
socket.Connect();
}
listener = new NmeaParser.StreamDevice(socket.InputStream);
}
catch (System.Exception ex)
{
socket?.Dispose();
socket = null;
status.Text += "\nError opening Bluetooth device:\n" + ex.Message;
}
}
if (listener != null)
{
listener.MessageReceived += Listener_MessageReceived;
status.Text += "\nOpening device...";
await listener.OpenAsync();
status.Text += "\nConnected!";
startButton.Enabled = !(stopButton.Enabled = true);
}
else
{
startButton.Enabled = !(stopButton.Enabled = false);
}
}
public BluetoothPrinterService()
{
BluetoothLowEnergy ble = new BluetoothLowEnergy();
Android.Bluetooth.BluetoothAdapter ba = null;
try
{
ba = Android.Bluetooth.BluetoothAdapter.DefaultAdapter;
if (null != ba)
{
try
{
Android.Bluetooth.State state = ba.State;
}
catch (Exception exc)
{
Android.Widget.Toast.MakeText
(
Android.App.Application.Context,
"Add bluetooth permission",
Android.Widget.ToastLength.Long
).Show();
}
}
}
catch (Exception exc)
{
string msg = "if this fails - AndroidManifest.xml";
LoggerService.WriteLine(msg);
}
if (ba == null)
{
LoggerService.WriteLine("BluetoothAdapter == null");
return;
}
if (!ba.IsEnabled)
{
LoggerService.WriteLine("Bluetooth adapter is not enabled.");
}
foreach (var bd in ba.BondedDevices)
{
LoggerService.WriteLine(bd.Name);
}
string device_name = "Qsprinter";
Android.Bluetooth.BluetoothDevice device =
(
from bd in ba.BondedDevices
where bd.Name == device_name
select bd
).FirstOrDefault();
if (device == null)
{
LoggerService.WriteLine("Bluetooth device not found = " + device_name);
}
Android.OS.ParcelUuid[] uuids = device.GetUuids();
string uuid =
uuids[0].ToString()
//Guid.NewGuid().ToString()
;
_socket = device
.CreateInsecureRfcommSocketToServiceRecord(Java.Util.UUID.FromString(uuid))
//.CreateRfcommSocketToServiceRecord (Java.Util.UUID.FromString (uuid))
;
try
{
_socket.Connect();
if (_socket.IsConnected)
{
LoggerService.WriteLine("Bluetooth socket connected ");
}
}
catch (Exception exc)
{
// [BluetoothUtils] isSocketAllowedBySecurityPolicy start : device null
// [BluetoothSocket] GlobalConfig.GLOBALCONFIG_BT_IT_POLICY_FEATURE = true
// [BluetoothAdapter] getBluetoothService() called with no BluetoothManagerCallback
// [BluetoothSocket] connect(), SocketState: INIT, mPfd: {ParcelFileDescriptor: FileDescriptor[78]}
}
byte[] data_bytes = System.Text.Encoding.UTF8.GetBytes("Bluetooth created");
// Write data to the device
//await
try
{
_socket.OutputStream.WriteAsync(data_bytes, 0, data_bytes.Length);
}
catch (Exception exc)
{
}
return;
}